Process and apparatus for the cracking of carbonaceous material



July 3, 1947- M. sTExNscl-ILAEGER PROCESS AND APPARATUS FOR THE CRACKING OF CRBONACEOUS MATERIAL Filed April 3, 1944 6 Sheets-Sheet 1 July s, 1947.

M. sr-ElNscHLAEGER 2,423,527

PROCESS AND APPARATUS FOR THE CRACKING OF CARBONACEOUS MATERIAL Filed April 3, 1944 6 Sheets-Sheet 2 M. s'rr-:lNscl-ILAEGER 2,423,527

Filed April 3, 1944 6 Sheets-Sheet 3 PROCESS AND APPARATUS FOR THE CRACKING 0F CARBONACEOUS MATERIAL July 8, 1947.

PROCESS AND APPARATUS FOR THE CRACKING QF CARBONACEOUS MATERIAL rJuly 8, 1947. M. s-rElNscHLAEGER t Filed April 3. 1944 6 Sheets-Sheet 4 July 8, 1947 M. sTElNscHLAEGER PROCESS AND APPARATUS FOR THE CRACKING OF CARBONACEOUS MATERIAL Filed April 5, 1944 I 6 Sheets-Sheet 5 July 8, 1947- M. STEINSCHLAEGER 2,423,527

PROCESS AND APPARATUS FOR THE CRACKING OF CARBONACEOUS MATERIAL Filed April 3, 1944 e sheets-sheet e ffy 2&3

Patented July 8, 1947 PROCESS AND APPARATUS FOR THE CRACKING F CARBONACEOUS MA- 'ITERIAL Michael Steinschlaeger, London, England Application April 3, 1944, Serial No. 529,388

lin Great Britain April 29, 1943 2 C. (Ci. 19o-67) i 2 This invention relates to a, process and apusing air or steam as the motive power for paratus for the cracking or partial or complete combustion of fuels and the generation of power.

The removal or separation of valuable products such as benzene, toluene and other liquid or gaseous hydrocarbons and other gases from cracking products is very expensive owing to the plant which has to be provided and the power and heat required.

To burn or crack oils such as gas oil, boiler oils, tars, pitches and the like, it has hitherto been essential to atomise or spray the oil or the like using steam or air at elevated pressure and in some cases with pre-heating and iiltering of the oil or the like.

Furthermore, by direct combustion of the oil and the like, a comparatively large excess of air is required for complete combustion, for example an excess of 60% above the theoretical, thus increasing the losses in the waste gases and decreasing the combustion temperature. Furthermore, in most cases the oil cannot be used advantageously in internal combustion engines.

It is an object of the present invention to provide a process and apparatus to overcome these disadvantages, and at the same time to obtain valuable hydrocarbon products.

According to the present invention a process is provided wherein fuel is partially or completely burnt in a burner, whereupon tar or oil or powdered pitch or powdered coal or hydrocarbon gases or a mixture thereof is mixed with the combustion gases, the sensible heat of the combustion gases being sulciently high to crack the oil or tar or powdered pitch or powdered coal or hydrocarbon gases, whereafter the cracking products are cooled in one or more heat exchangers, and if they are not already under a suihcient degree of pressure are compressed to a degree sulllcient to cause condensation of a part of the cracking products or combustion products and the remainder thereof is passed through one or more of the aforesaid heat exchangers to increase the temperature thereof. The gases are then passed through one or more gas turbines.

Examples of hydrocarbon gases which may be cracked in the process are natural gas and coke Oven gas.

Preferably the fuel employed for providing the heat is a, small proportion of the oil or tar or powdered pitch or powdered coal or hydrocarbon gases to be cracked, and once the process has been started a small proportion, for example 5 to of the gas produced may be re-cycled and used as the fuel for producing the heat required re-cyeling.

If desired the process of the invention may be operated under pressure, and catalysts may be employed.

Both the primary and secondary air and also the fuels used in the process may. if desired, be pre-heated.

The cracking in the burner may be eiected in stages by introducing the oil or the like at a plurality of points and if desired different kinds of oil or powdered .pitch or powdered coal or tar or hydrocarbon gases may be introduced at these diiierent points.

The invention also includes an apparatus for carrying out the process of the invention comprising a. burner having inlets for fuel and air for combustion at one end, a conduit for introducing oil or tar or powdered pitch or powdered coal or hydrocarbon gases into the combustion products, an outlet conduit for removing the cracking products, a compressor for compressing the air or the cracking products and one or more heat exchangers for heat exchange between the aforesaid gases.

The invention further includes a. burner comprising a chamber, an inlet for fuel and air for combustion at one end, one or more inlets for injecting the oil, tar, or powdered pitch or powdered coal or hydrocarbon gases, a conduit containing an injector, said conduit connecting the fuel inlet and the chamber at a point beyond the rst inlet for oil, tar, or powdered coal or powdered pitch or hydrocarbon gases, and an outlet for the products produced.

Preferably also the burner contains one or more inlets for secondary air.

1t should be understood that the term "air" as used herein includes other oxygen-containing gases and also oxygen with or without the addition of steam or carbon dioxide.

In the burner, tar or oil or gas may be partially burnt for the generation of producer gas,

rwater gas and combustion gases or mixtures of power generation.

This modification may also be used advantaapparatus for carrying into effect the processes of the invention.

Referring to Fig. 1 of the drawings, hydrocarbon gas or oil is supplied to the burner I through conduit 2 controlled by valve 2a under increased pressure and oxygen or air or oxygenenriched air is supplied to the burner through conduit 3 controlled by valve 3a, whilststeam and/or carbon dioxide also under pressure is slmilarly supplied through conduit 4 controlled by vvalve 4a. Hydrocarbon-containing gases are passed through conduit 5 controlled by valve 5a through the heat exchanger 6 where they are and passing through the heat exchanger 28 -to the gas turbine 42 from' which the gases leave via A conduit 43 controlled by valve 43a, part being heated and then passed through conduit il controlled by valve 1a into the burner I, in which they are cracked by the hot combustion products. The hot combustion products containing the cracked hydrocarbon gases leave theburner I through conduit 8 controlled by valve 8a and pass through heat exchanger 9, in which they are cooled, and thence by conduit I0 -controlled by valve lila to heat exchanger I I, in which they are further cooled and thence through conduit l2 controlled by valve |2a into the cooler and precipitator i3, in which easily liquefied gases and vapours are condensed, and leave via conduit ill controlled by valve I4a. 'I'he uncondensed gases are then heated by' passing through heat exchanger il, through conduit I5 controlled by valve |5a, thence passing to the gas turbine i6 from which they pass via conduit |1 controlled by valve I'la through heat exchanger 9 to the gas turbine I8, from which they 'leave by conduit i9 controlled by Valve |9a, passing through the boiler or heat exchanger 20 and thence to the consumer at atmospheric or increased pressure, as desired.

Referring to Fig. 2 of the drawings, oil and/or tar and/or hydrocarbon gases is admitted into burner 2i through conduit 22 controlled by valve 22a and air and/or oxygen is introduced via conduit 23 controlled by valve 23a., whilst steam and/or carbon dioxide is introduced through conduit 24 controlled 'by valve 24a. 'Ihe oil and/or tar and/or gas is burnt in the burner and oil and/or hydrocarbon gases for cracking is admitted through conduits 25 and 26 controlled respectively by valves 25a and 26a. The products of combustion carrying the cracking products leave through conduit 21 controlled by valve 21a, and pass through heat exchanger 28 and conduit 29 controlled by valve 29a to heat exchanger 30, and thence via conduit 3I controlled by valve 3 la to compressor 3 Ib Where -they are compressed and then passed to cooler and precipltator 32, in which vapours and easily liquefied gases are condensed and are removed through conduit 33 controlled by valve 33a. The uncondensed gases leave through conduit 34 controlled by valve 34a. and pass through the activated carbon plant 35, and thence via conduit 36 controlled by valve 36a to the compressor 31, and thence through the iurther activated carbon plants 38 and conduit 39 controlled by. valve 39a through heat exchanger to the gas turbine 40, the gases leaving the turbine 40 via conduit 4| lcontrolled by valve 4|a,

sent to the consumer and another part passing via conduit 44 controlled by valve 44a through boiler or heat exchanger 45, a part of the gas being then re-cycled to the conduits 39 and 4I (as shown) by conduits 46 and 41 controlled respectively by valves 46a and 41a, further parts of the gas being re-cycled to the burner 2i via conduit 48 controlled by valve 48a, and to the conduit 2E via conduit 49` controlled by valve 69a.

Refering now to Figure 3 of the drawings, air is admitted through conduit 50 controlled by valve 50a to the compressor 5| which it leaves 'under pressure through conduit 52 controlled by valve 52a, oil and/or gasesv beingv injected therein through conduit 53 controlled by valve 53a. The mixture then passes into the burner 54 in which it is burnt, and oil and/cr hydrocarbon gases admitted through conduits 55 and 56 controlled respectively by valves 55a and 56a. is cracked by the combustion products. The combustion and cracking products leave via conduit 51 controlled by valve 51a and pass through the heat exchanger 58 and conduit 59 controlled by valve 58a to the heat exchanger 60, and thence via conduit 6| controlled by valve 6 Ia, to the cooler and precipitator 62 in which liquid hydrocarbons and easily liqueed gases and vapours are precipitated and are removed via conduit 63 controlled by valve 63a., a part of the uncondensed gases being also removed via conduit 64 controlled by valve 64a, the remainder passing through conduit 65 controlled by valve 65a through heat exchanger 60 to the gas turbine 66, the gases leaving which pass through conduit 61 controlled by valve 61a through the heat exchanger 58 to the gas turbine 68, from which the gases leave via conduit 65 controlled by valve 69a and pass to the with the required pressure.

Referring to Fig. 4 of the drawings, air is introduced through conduit 86 controlled by valve 86a`into the compressor 81 from which the air leaves under lpressure via conduit 88 controlled by valve 88a, and passes through heat exchanger 89 to the gas turbine 90, whence it passes via conduit 9| controlled by valve 9|a through heat exchanger 92 into the gas turbine 93, whence the air leaves, still'under pressure, through conduit 94 controlled by valve 94a, a part of the air then being passed via conduit 95 controlled by valve 95a into which oil and/or tar is admitted through conduit 96 controlled by valve 96a, the mixture being burnt in the burner 91, oil and/or tar being introduced through conduit 98 controlled by valve 98a. into the combustion products in which the oil and/or tar i5 cracked, the mixture of combustion and cracking products leaving via conduit 99 controlled by valve 99a, thence passing through heat exchanger 92 and conduit |00 controlled by valve |00a to the heat exchanger 89, and thence via conduit |0| controlled by valve I0|a to the cooler and precipitator |02 in which tar is condensed and removed through conduit |03 controlled by valve I03a, the gas leaving the cooler and precipitator through conduit |04 controlled by valve I04a, part of the gas then passing through conduit |05 controlled by valve I05ainto the internal combustion engine |06, which is fed by the remainder of the compressed air from conduit 94 via conduit |01 controlled by valve |01a passing through the cooler |08 before reaching the internal combustion engine. The exhaust gases from the internal combustion engine leave 5 via conduit |09 controlled by valve |09a and pass through the boiler or heat exchanger and are used for power generation. The remainder of the gases from conduit |04 proceed via conduit controlled by valve Illa and are recycled to conduits 88 and 9| as shown, via conduits I2 and ||3 controlled respectively by valves |2a and |3a for combustion.

Referring to Fig. 6 of the drawings, air is admitted through conduit ||4 controlled by valve I |4a into the compressor I |5, from which it leaves under pressure through conduit ||6 controlled by valve |6a. Oil and/or tar is admitted through conduit ||1 controlled by valve ||1a and the mixture is burnt in the burner H8, into which oil and/or tar is admitted through conduit ||9 controlled by valve |l9a, the oil and/or tar being cracked by the sensible heat of the combustion products. The mixture of combustion products and cracking products leaves via conduit I|20 controlled by valve |20a and proceeds through heat exchanger |2| via conduit |22 controlled by valve |22a through heat exchanger |23 and thence via conduit A|24 controlled by valve |24a to the cooler and precipitator |25, in which liquid hydrocarbons and easily liqueed gases are condensed and removed through conduit |26 controlled by valve |26a. The uncondensed gases leave via conduit |21 controlled by valve |21a in which the gases split into two streams, one part going via conduit |28 controlled by valve |28a to the combustion chamber |29 and the other part via conduit |30 controlled by valve I30a to the combustion chamber |3|, air for the combustion in the combustion chamber |29 being supplied from the compressor via conduit |32 controlled by valve |32a, the air being pre-heated in the heat exchanger |23. The combustion products leaving the combustion chamber |29 contain excess oxygen and proceed under pressure through conduit |33 controlled by valve |33a through the gas turbine |34 and conduit |35 controlled by valve |35a through the heat exchanger |2| to the combustion chamber |3|, in 'which further combustion takes place. The combustion gases leave the combustion chamber via conduit |36 controlled by valve |36a, passing through the gas turbine |31 and thence by the conduit |38 controlled by valve |38a, and may be used for pre-heating or steam raising.

Referring to Fig, 6 of the drawings, which illustrates a burner according to the invention, air is supplied through conduit |39 controlled by valve 39a to the blower |40 which supplies air under pressure through conduit |4| controlled by valve |4|a to the burner |42, fuel being'supplied through conduit |43 controlled by valve |43a. Oil and/or powdered coal is introduced through con.. duit |44 controlled by valve |44a into the combustion gases which crack the oil or coal and the mixture of combustion gases and cracking products leave via conduit |45 controlled by valve |45a, part of the gases are re-cycled via conduit |43b controlled by valve |43c to the conduit |43 and the remainder of the gases is burnt in a boiler |46 by means of air supplied under pressure through conduit |41 controlled by valve |41a. The waste gases which leave the boiler through conduit |48 controlled by valve |48a may be used for pre-heating air or the like.

Referring to Fig. 7 of the drawings, air is admitted via conduit |49 controlled by valve |49a into the compressor |50, from which it leaves under pressure via conduit |5| controlled by valve |5|a passing through the heat exchanger |52 into the gas turbine 53, from which it leaves via conduit |54 controlled by valve |54a, passing through heat exchanger |55 into the gas turbine |56. Part of the air, still under pressure. leaves the turbine through conduit |51 controlled by valve |51a, oil and/or tar and/or powdered coal being injected therein through conduit |58 controlled by valve |58a, and the mixture is burnt in the burner |59. Oil and/or tar and/or powdered coal is introduced through conduit |60 controlled by valve |60a and is cracked by the sensible heat of the combustion products. The mixture of combustion products and cracking products leaves via conduit |6| controlled by valve |6|a, proceeding through heat exchanger |55, conduit |62 controlled by valve |62a, heat exchanger |52 and con duit |63 controlled by valve |63a to the 'cooler and precipitator |68 in which liquid hydrocarbons are condensed and removed through conduit |69 controlled by valve |69a. The uncondensed gases leave via conduit |10 controlled by valve |10a and proceed to the boiler |64, in which they are burnt by means of air supplied under pressure through conduit controlled by valve |65a; a further part of the air under pressus`^ being supplied to the consumer via conduit |65 controlled by valve |66a. The waste gases leave the boiler via conduit |61 controlled by valve |61a and can be used for heating purposes, or allowed to escape through the chimney stack of the boiler.

Referring to Fig. 8 of the drawings, a hydrocarbon gas such as methane, natural gas, coke oven gas, a residual gas from a Fischer-Tropsch or similar synthesis process or from a hydrogenation process is introduced (if it contains hydrogen sulphide) through conduit |1| controlled by valve |1|a into the purication chamber |12 for the removal of hydrogen sulphide. The puried gas then passes through conduit |13 controlled by valve |13a into the compressor |14 from which thevgas leaves under pressure 'through conduit |15 controlled by valve |15a, a part passing into the burner |16 in which it is burnt by oxygen admitted through conduit |11 controlled by valve |11a and steam admitted through conduit |18 controlled by valve |18a. 1f desired the gas passing through conduit |15 may be pre-heated before entering the burner (by means not shown) The remainder of the gas passes through conduit |19 controlled by valve |19a into the combustion products, which have su'icient sensiblel heat to crack the gases. The mixture of" cracking and combustion products leaves via conduit controlled by valve |80a, passing through the boiler |8| and heat exchanger |82, conduit |83 controlled by valve |83a, heat exchanger |84 and conduit |85 controlled by valve |85a to the carbon dioxide removal plant |86, where the carbon dioxide is liquefied and removed through conduit controlled by valve |95a. Instead of the boiler |8| there may be used one or more regenerators. The uncondensed gases leave via conduit |81 controlled by valve |81a and pass through the heat exchanger |84 into the gas turbine |88, from whence they pass via conduit |89 controlled by valve |89a into the gas turbine |90. If more power is required steam or other gases may be admitv ted through conduit 81h controlled by valve |81c.

'Ihe gases leaving the turbine |90 by the conduit |9| controlled by valve |9|a pass to the organic sulphur purifying plant |92 (if it is desired to remove any organic sulphur compound presenti from whence they are sent to the consumer at the desired temperature and pressure through conduit |93 controlled by valve |93a, after passing through heat exchanger |94.

Referring to Fig. 9 of the drawings, air is admitted through conduit 204 controlled by valve 204a into the compressor 205, from which the air leaves under pressure through conduit 206 controlled by valve 206a, passing through heat exchanger 201 to the gas turbine 208, whence the air leaves, still under pressure, through conduit 209 controlled by valve 209a, passing through heat exchanger 2|0 to the gas turbine 2| from which the air leaves, still under pressure, through conduit 2|2 controlled by valve 2|2a. Oil and/or tar is admitted through conduit 2|3 controlled by valve 2|3a, and the mixture is burnt in the burner 2|4. The combustion gases leave through conduit 2|5 controlled by valve 2|5a, and oil and/or tar is admitted through conduit 2|5 controlled by valve 2 |6a, and is cracked by the sensible heat of the combustion gases. The mixture of combustion products and cracking products passes through heat exchanger 2|0 and thence via conduit 2|1 controlled by valve 2|1a through heat exchanger 201, through conduit 2|8 con.. trolled by valve 2| 8a into a cooler and precipitator 2|9, from which condensed liquid hydrocar-4 bons and easily liqueed gases are removedvia conduit 220 controlled by valve 220a. The uncondensed gases leave via conduit 22| controlled by valve 22| a and are compressed in the compressoi- 222. A part of the gases is sent to the consumer under the desired pressure through con-` duit 223 controlled by valve 223a, the remainder being recycled via conduit 224 controlled by Valve 224a to the cooler and precipitator 2|9 or to other parts of the plant (by means not shown).

Referring to Fig. of the drawings, air is admitted through conduit 225 controlled by valve 22511 into a multi-stage compressor 226. Part of v the air from the compressor leaves via conduit 221 controlled by valve 221a and is used to burn oil and/or tar and/or hydrocarbon gases admitted through conduit 228 controlled by valve 228a in burner 229. Oil and/or tar is admitted through conduit 230 controlled by valve 2300, and is cracked by the sensible heat of the combustion products. The mixture of combustion and cracking products leaves via conduit 23| controlled by passing through heat exchanger 234 to the gas turbine 239, from which the gases leave, still under pressure, through conduit 240 controlled by valve 24|la, through the` heat exchanger 232 to the gas turbine 24|, from which the gases leave, still under pressure, through conduit 242 controlled by valve 242e, passing through heat exchanger 243, to the internal combustion engine 244. Air is also supplied under compression from the compressor 226 at the same or different'pressure from that obtaining in the conduit 221 through conduit 245 controlled by valve 245a, which supplies air to the internal combustion engine for combustion. If desired, a part of the air mayalso be sent through conduits 246 and 24% controlled respectively by valves 2460J and 2,41a to the conduits 238 and 240 respectively, in

part or the whole of the air may proceed via conduit 248 controlled by valve 248a, through heat exchanger 243 and conduit 249 controlled by valve 249a, to the internal combustion engine 244. The gases leaving the internal combustion engine pass through heat exchanger 250 via exit conduit 25| controlled by valve 25|a. A part of gases in the conduit 242 may be re-cycled via conduit 252 controlled by valve 252a, to conduit 228.

Referring now to Fig. 11 of the drawings, air is admitted through conduit 253 controlled by valve 253a, and is cooled in the heat exchanger 254, passing via conduit 255 controlled by valve 255a to a multi-stage compressor 256. The air under pressure leaves via conduit 251 controlled by valve 251a, passing through heat exchanger 258. The air then passes through the throttle valve 259 in which it expands, liquid 'air or gaseous components thereof under pressure leaving via conduit 260 controlled by valve 260a, and gaseous air passing through conduit 26| controlled by valve 26|a through heat exchanger 258 to conduit 262 controlled by valve 262a. This air is then split into two streams, a part being recycled via conduit 263 controlled by valve 263a to conduit 255 and the other part being sent via conduit 264 controlled by valve 264a through heat exchanger 254 to the burner 265. Into the burner there is also admitted oil and/or hydrov carbon gas through conduit 266 controlled by valve 266a, and steam and/or carbon dioxide through conduit 261 controlled by valve 261a. Oil and/or hydrocarbon gas is admitted through conduit 268 controlled by valve 26811 into the combustion products in the burner 265 and is cracked by the sensible heat thereof. The mixture of combustion and cracking products leaves via conduit 263 controlled by valve 26911, and proceeds via heat exchanger 210, conduit 21| controlled by valve 21|a, through heat exchanger 212 and conduit 213 controlled by valve 2136:, to the cooler and precipitator 214, from which. condensed hydrocarbons and liquefied hydrocarbon gases are removed via conduit 215 controlled by valve 215e. The uneondensed gases leave the cooler and precipitatcr through conduit 216 conrolled by valve 216a through which a part of the gases is sent to the consumer and the remainder is' sent to the conduits 211 and 218, controlled respectively by valves 211a and 218a, for the purposes hereinafter specified. Air is also supplied from conduit 264 through a branch conduit 219 controlled by valve 219a, through heat exchanger 212 to the gas turbine 280, gases being admitted through the aforesaid conduit 218. The gases leaving the turbine 280 proceed via conduit 28| controlled by valve 28|a through heat exchanger 210 to the gas turbine 282, further gases for heating being admitted through the aforesaid conduit 211. The gases leaving the turbine`282 proceed via conduit 283 controlled by valve 283a to a heat exchanger or boiler.

In connection with refrigeration processes the gasesor media used for refrigeration may be A,bines by utilising the sensible heat of the gases produced.

In connection with synthesis processes such as Fischer-Tropsch processes, ammonia synthesis processes and hydrogenation or refining processes, gases such as carbon monoxide, hydrogen and nitrogen and mixtures of the same may be produced in the required purity and concentration. y

The entire power and steam and a surplus, if required, may be generated in the way shown above.

The oxygen or other gases required for some ofthe modifications may also be obtained cheaply by utilising this process.

The term oil as used in the appended claims means oil or tar or powdered pitch or powdered coal or hydrocarbon gases or a mixture thereof.

I claim:

1. A continuous process for the cracking of oil and the generation oi' power which comprises at least partially burning a fuel in a burner to produce combustion gases, mixing oil with said combustion gases, the sensible heat of the said combustion gases being sumciently high to crack the oil, passing the mixture of cracking products and combustion gases through two heat exchangers in series to cool said mixture, passing said cooled mixture through a cooler to remove tar, heavy ludrocarbons and steam, passing the uncondensed residue through a compressor to cause condensation of further constituents of the mixture and raise the pressure, heating the co'mpressed mixture by passing it through' one of said heat exchangers, passing the heated mixture still under pressure through a gas turbine, heating the exit gases from said turbine by passing them through the other ci said heat exchangers and passing the heated gases still under pressure through a second gas turbine.

2. A cracking apparatus comprising a burner having inlets for fuel and air for combustion at one end. a 'conduit for introducing oil into the for removing the mixture of cracking products and combustion gases from said burner, two heat exchangers connected inY series to said outlet, a cooler, a conduit connecting the outlet of the second of said heat exchangers to the cooler, a compressor, a conduit connecting said cooler to said compressor, two gas turbines in series, a conduit connecting said turbines and a conduit connecting said compressor and the inlet of the rst of said turbines, said last two conduits each forming a part of one of said heat exchangers.

MICHAEL S'I'EINSCHLAEGER.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS 20 Number Name Date 1,295,825 Ellis Feb. 25, 1919 1,784,126 Beardsley Dec. 9, 1930 1,490,862 Smith Apr. 15, 1924 1,922,322 Penniman Aug. 15, 1933 25 1,933,048 Coleman Oct. 31, 1933 1,966,790 Ellis July 17, 1934 2,016,798 Cooke Oct. 8, 1935 2,046,501 Cooke July 7, 1936 2,091,375 Pyzel Aug. 31, 1937 80 2,176,453 Clark -Oct. 17, 1939 2,272,209 Keeling Feb. 10, 1942 1,687,595 Shore Oct. 16,1928 2,222,489 Riggs Nov. 19, 1940 1,907,029 Andrews et al May 2, 1933 35` 2,167,655 Houdry et al. Aug. 1, 1939 2,141,633 Wolf et al. Dec. 27, 1938 2,167,698 Vose Aug. l, 1939 combustion products in said burner, an outlet 

